Scared off falling out with my sister if I say something

[Rose220]

Today i started my dreaded period. I'm always sensitive around this time. Only something has been bothering me for months and I have cried alday over it. My daughter and neice are almost the same age 9 months between them. Only my niece is always so rough nasty and horrible to my daughter. There only 3. She's always throwing things at her pushing her, pulling her hair. And my sister doesn't really tell her daughter off. In my sister eyes her daughter can't do anything wrong. Only my daughter never cries but always cries when they come over. I'm now finding myself making excuses and avoiding meeting up with them. But I feel like the bad guy but my heart breaks seeing my daughter hurt and sad. But when I speak to my sister I'm just told I'm being to over sensitive. Any advice as I'm just avoiding meeting up with them.

I have this a little with my DD 3 and my sisters DS 3 (5 weeks apart). Whilst she isn't that flaky she does let him get away with more than I would but I just tell him off if she doesn't. She has said she thinks I'm too hard on my DDs but then again you can take mine anywhere and they will behave. She's won't take him out really for fear of his behaviour. Says it all really.

Do they go to a pre school? Was thinking if the did the nursery/pre school wouldn't allow this and intervene.

My daughter goes to morning nursery and my niece goes to full time childcare as my sister works full time. My kids are great I can take then anywhere and they are always with me. My sister works full time and is scared of telling her daughter off as she doesn't want to be the bad guy. I believe no matter if you work or not children need to now between right and wrong. Last week my niece was round mine she turned my oven on, through toys around the living room, snatched toys off my daughter and pushed her and my sister told her how good she had been. 3 weeks ago the girls were in the garden playing and my niece shut the garden gate on my daughter and laughed my daughter was screaming and my sister called her husband and all he said was when she gets home daddy would give her a treat I was fuming.